7/16/2018 Aircraft Holding Procedures Aircraft Holding Procedures Introduction: Holding becomes necessary when there is a need to keep air traffic within specified airspace that is reasonably protected Different types of holding patterns are established, based on their purpose and phase of flight Holding itself and consists of several holding orbits which the pilot must maintain Upon receipt of a holding clearance from Air Traffic Control (ATC), pilots will execute holding procedure Can be accomplished at a NAVAID, a fix, or an intersection A NAVAID (or Navigational Aid) is defined as any visual or electronic device airborne or on the surface which provides point­to­point guidance information or position data to aircraft in flight A fix is defined as a geographical position determined by visual reference to the surface, by reference to one or more radio NAVAIDs, by celestial plotting, or by another navigational device An intersection is defined by a point defined by any combination of courses, radials, or bearings of two or more navigational aids Practice is critical as this can be a perishable skill While holding is an IFR task, it can be performed by aircraft flying under VFR under certain circumstances Figure 1: Instrument Approach Procedures Holding Patterns Reasons to Hold: Traffic congestion, Aircraft emergency, Equipment outage, Waiting for an Expect Further Clearance time, Pilots require time to make a decision, Poor weather, or Unavailability of the runway Types of Holding Patterns There are 3 types of holding, depicted in the instrument approach chart legend: [Figure 1] 1. Holding in lieu of procedure turn: Depicted as a solid bold line on an instrument approach In practice, holding in lieu is not really a holding pattern, but a method by which to turn around (course reversal) http://www.cfinotebook.net/notebook/maneuvers-and-procedures/instrument/aircraft-holding-procedures 1/16 7/16/2018 Aircraft Holding Procedures When used, you do not need to go outbound for the full distance but rather after 1 minute you should turn back in and execute the approach 2. Arrival Pattern Arrival patterns are used to control the flow of traffic on an approach Depicted as a thin solid line on instrument charts Think of it as adding a delay to ensure the airport environment is clear The arrival holding pattern is not authorized unless assigned by ATC 3. Missed Approach Visually depicts holding following the execution of a missed approach Depicted as a dashed line on instrument approach procedure This pattern is considered the "published missed" Many times ATC will assign alternate instructions to facilitate traffic flow, especially during practice approaches Holding Pattern Airspace Protection: Holding areas must be designated as protected, i.e., free from obstacles Holding pattern airspace protection is therefore provided by controlling the pattern's size: Holding Pattern Layout: The FAA's standard pattern consists of right turns (Think that most people are right handed, making that standard) Although nonstandard, left turns may be assigned Note that holding patterns depicted in the instrument approach plate legend show both left and right turns and are in no way an indication of standards Holding Pattern Altitude Clearly, obstacle protection increases with altitude More importantly, altitude impacts airspeeds due to the operation (aircraft operating at higher altitudes fly faster) The standard altitude blocks that we are concerned with are: Surface to 6000 feet MSL 6001 feet to 14,000 feet MSL and 14,001 feet MSL and higher These altitude blocks generally correspond to maximum airspeeds Holding Pattern Airspeeds: Holding is generally performed at max endurance, to conserve fuel Holding patterns may be restricted to a maximum speed ATC: "[Callsign] [holding instructions], maximum holding speed is [Speed in Knots]" Holding speeds are based on an expected turn radius to keep pilots clear of obstacles The speed restriction is depicted in parenthesis inside the holding pattern on the chart: e.g., (175) Pilots unable to comply with the maximum airspeed restriction should notify ATC The aircraft should be at or below the maximum speed prior to initially crossing the holding fix to avoid exiting the protected airspace Below 6,000' MSL: 200 KIAS 6001' MSL to 14,000' MSL: 230 KIAS Holding patterns from 6,001’ to 14,000’ may be further restricted to a maximum airspeed of 210 KIAS, but will be depicted or dictated in the clearance as such 14,001' MSL and up: 265 KIAS Note that holding speeds change at 14,001 (as does the holding time (1.0 to 1.5 minutes)) U.S. Air Force Airfields: 310 KIAS U.S. Navy Airfields: 230 KIAS All helicopter/power lift aircraft holding on a "COPTER" instrument procedure is predicated on a minimum airspeed of 90 KIAS unless charted otherwise When a climb­in hold is specified by a published procedure (i.e., "Climb­in holding pattern to depart XYZ VORTAC at or above 10,000." or "All aircraft climb­in TRUCK holding pattern to cross TRUCK Int at or above 11,500 before proceeding on course"), additional obstacle protection area has been provided to allow for greater airspeeds in the climb for those aircraft requiring them A maximum airspeed of 310 KIAS is permitted in Climb­in­holding, unless a maximum holding airspeed is published, in which case that maximum airspeed is applicable Where the holding pattern is restricted to a maximum airspeed of 175 KIAS, the 200 KIAS holding pattern template has been applied for published climb­in hold procedures for altitudes 6,000 feet and below and the http://www.cfinotebook.net/notebook/maneuvers-and-procedures/instrument/aircraft-holding-procedures 2/16 7/16/2018 Aircraft Holding Procedures 230 KIAS holding pattern template has been applied for altitudes above 6,000 feet The airspeed limitations in 14 CFR Section 91.117, Aircraft Speed, still apply The following phraseology may be used by an ATC to advise a pilot of the maximum holding airspeed for a holding pattern airspace area: "[Callsign], [Holding instructions, when needed], maximum holding airspeed is [Speed in knots]" Holding Pattern Timing: Some aircraft will have their own timers but you can just as easily bring your own Flight Timer/watch to mount to the aircraft or kneeboard Inbound Leg: At or below 14,000' MSL, legs should be timed to equal 1 minute Above 14,000' MSL, legs should be timed to equal 1 and 1/2 minutes In order to remember this rule, remember that no one will make you hold at 14,001' but rather 14,000 or 15,000 most likely. The 1.5 minute leg comes to play at 15k 10% RULE: 15 = 1.5 min Timing inbound is measured from the point that the aircraft is wings level, inbound to the holding fix, to the time the aircraft crosses the holding fix Outbound Leg: Outbound time is adjusted to achieve the correct inbound timing Outbound leg timing begins over/abeam the fix, whichever occurs later If the abeam position cannot be determined, start timing when the turn outbound is completed Abeam is when the needle drops below the 90° benchmark in the HSI, not the TO/FROM flip The initial outbound leg should be flown for 1 minute or 1 1/2 minutes (appropriate to altitude) Pilots may use any navigational means available; i.e., DME, RNAV, etc., to ensure the appropriate inbound leg times Timing is generally associated with VOR holding, but some TACAN holds may require timing if no DME specified Holding protected airspace is designed based in part on pilot compliance with the three recommended holding pattern entry procedures discussed below Deviations from these recommendations, coupled with excessive airspeed crossing the holding fix, may in some cases result in the aircraft exceeding holding protected airspace http://www.cfinotebook.net/notebook/maneuvers-and-procedures/instrument/aircraft-holding-procedures 3/16 7/16/2018 Aircraft Holding Procedures Figure 2: Holding Pattern Entry Procedures Holding Orbits: Holding consists of several orbits in an oval shaped pattern The first orbit is the entry orbit which expeditiously establishes the aircraft inbound on the holding courses The second orbit is the no­wind orbit which sets the baseline from which all corrections can then be made The last orbit flown is the correction orbit which updates and refines the wind corrections Entry Orbit: The entry orbit establishes the aircraft into the holding pattern There are three types: the direct, parallel, and teardrop entry Direct Entry: When approaching the holding fix from anywhere in sector (c), the direct entry procedure would be to fly directly to the fix and turn to follow the holding pattern [Figure 2] Parallel Entry: When approaching the holding fix from anywhere in sector (a), the parallel entry procedure would be to turn to a heading to parallel the holding course outbound on the non holding side for one minute, turn in the direction of the holding pattern through more than 180 degrees, and return to the holding fix or intercept the holding course inbound [Figure 2] Right Turns: first turn left, then left, then right Left Turns: first turn right, then right, then left Teardrop Entry: When approaching the holding fix from anywhere in sector (b), the teardrop entry procedure would be to fly to the fix, turn outbound to a heading for a 30 degree teardrop entry within the pattern (on the holding side) for a period of one minute, then turn in the direction of the holding pattern to intercept the inbound holding course [Figure 2] Remember Left Add Right Subtract, or LARS for short L+30 R­30 While other entry procedures may enable the